Sleep Pattern Trajectories and Incident Mild Cognitive Impairment and Dementia: Results from the HELIAD Study.

OBJECTIVES

We explored the trajectories of sleep patterns and their relationship with conversion to MCI or dementia in a sample of older adults.

METHODS

A total of 1984 participants ( >64 years old) in a population-based, longitudinal study (HELIAD), provided information regarding their sleep patterns. A full neurological exam and a comprehensive neuropsychological assessment were conducted to determine MCI and dementia diagnoses. Baseline and three-year follow-up associations of sleep patterns with cognitive status (healthy, MCI, dementia), age, education and sex were analyzed with the utilization of generalized estimating equation models.

RESULTS

Baseline sleep patterns did not differentiate between initially healthy participants who converted either to MCI or dementia and those who remained healthy at follow-up. Baseline healthy participants who converted to MCI at follow-up reported more frequent sleep quality problems at follow-up than the consistently healthy participants (p = .032). Baseline healthy participants who converted to dementia at follow-up conveyed less frequent sleep disturbances(p = .009), greater sleep adequacy ratings (p = .006) and longer sleep duration (p = .001) at follow-up compared to their consistently healthy counterparts.

CONCLUSIONS

Sleep pattern trajectories were not associated with cognitive diagnosis. Sleep pattern alterations do not appear to predate conversion to MCI or dementia among cognitively healthy older adults.

CLINICAL IMPLICATIONS: Discrepancies in self-reports might reflect a compromise in the ability to form objective judgments. These discrepancies may help differentiate between MCI and early dementia.